Storage system and its access control method

Abstract

A storage system configuring a logical storage device by dividing an area on a physical storage space formed by a group of several physical storage devices by the unit of physical block having a certain block length and by assigning the physical storage space in every physical block, comprises a logical storage control table which records identification information indicating whether a physical block is assigned to data or operation is bound to data created from a predetermined data arrangement pattern in every area on the logical storage device, and a data writing unit which, upon receipt of a request of writing data into an area of the logical storage device, when a data arrangement pattern of the writing request agrees with a previously-registered data arrangement pattern, records the identification information of the same data arrangement pattern into the logical storage control table correspondingly to the writing-requested area and abandons the writing request data.

Description

BACKGROUNDS OF THE INVENTION [0001] b 1. Field of the Invention [0002] The present invention relates to a storage system configuring a logical storage device by dividing the area on a physical storage space formed by a group of several physical storage devices by the unit of physical block having a certain block length and by assigning the physical storage space in every physical block, and more particularly to a storage system and its access control method for improving efficiency of assignment of physical storage devices. [0003] 2. Description of the Related Art [0004] Heretofore, there has been such a storage system as forming a logical storage device by a group of several physical storage devices, like a disk array device represented by RAID (Redundant Arrays of Inexpensive / Independent Disks). Data to be stored in the logical storage device on this storage system will be dispersed and stored in each storage area on several physical storage devices. [0005] Holding a table for bri...

AI Technical Summary

Benefits of technology

[0014] In order to solve the above conventional problem, an object of the invention is to provide a storage system, forming a logical storage device by a group of several physical storage devices, and its access control method in which the assignment efficiency of physical storage devices can be improved and the cost can be decreased.

[0017] According to the invention, as far as the writing request data as for a storage system follows the data arrangement pattern, assignment of an area on a physical storage device is not necessary, hence to improve the assignment efficiency of a physical storage device and decrease the cost of the storage system.

Problems solved by technology

This storage system having such redundancy has such a problem that volume required by each physical storage device is increased according as store data is increased in size, also accompanied by increase in cost.

The above-mentioned conventional techniques, however, have the following problems.

The conventional storage system has a problem of hindering efficient assignment of physical storage devices because there necessarily exists some physical storage device for storing write data with respect to an area on a logical storage device.

Though some kind of program running on the host computer (file system, volume control program, backup recovery program, etc.) writes data of specified data storage format (arrangement pattern of data) into a storage system, the conventional storage system cannot cope with the processing depending on the data storage format (arrangement pattern of data) and it always assigns the area on a physical storage device with respect to the area relative to a writing request.

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